1. Field of the Invention
The present invention relates to automated machinery for crimping caps onto containers and, more particularly, to a collet crimping head for gripping, installing and crimping container caps onto containers during an automated high-volume filling and capping process.
2. Description of the Background
The filling and capping process generally entails supplying containers along a conveyor, automatically filling them at a filling station, and automatically capping them at a capping station. Various testing and control functions may be performed along the way, e.g., testing and control of fill volume, conveyor velocity, etc. The apparatus which performs the process must be capable of accommodating a wide variety of containers and caps (both caps and containers may vary in size and shape), and this is accomplished by a universal chuck which allows quick and easy grasping and manipulation of different cap sizes.
In U.S. patent application Ser. 09/222,475 entitled "QUICK-CHANGE COLLET CHUCK", filed Dec. 29, 1998, the inventor herein explained that many caps are intended for screw-insertion onto containers, and a variety of automated collet chucks exist for positioning and torquing of such caps. The above-referenced application describes how a low-inertia collet-type chuck which has proven itself far superior to conventional Donut Chucks and the Segmented Jaw Chucks. This is in part because the collet design has a much broader operative range. In addition, the disclosed collet chuck offers a quick-change feature for quick and effortless swapping out of different size jaw sets for different size caps. The collet itself is a low cost one-piece component with a number of downwardly protruding tines for gripping a cap. The collet may have urethane-lined jaws to drive caps with lower torque requirements, or machined contact is profile jaws to drive caps with high torque requirements (positive interlocking with the external cap profile). Given either arrangement, even asymmetric caps can be clamped into the collet without requiring a special chuck change (collet orientation relative to the chuck is always an exact repeat and servo drive allows an exact chuck orientation repeat). There is virtually no down time (or skill level) associated with the collet change.
The above-described collet chuck was designed for caps that require screw-insertion onto containers. However, many other caps are crimped onto containers. FIGS. 1-3 generally illustrate the crimping process.
FIG. 1 is a front view of a pharmaceutical vial 30 with a conventional read seal over-cap including plastic cap 10 and aluminum hood 20. The crimping process begins vial 30 or other container formed with a neck, and a cap having a deformable aluminum hood 20 to be crimped around the neck of the vial 30. As is known in the art, plastic cap 10 is bonded to the hood 20 but can be removed to expose a sealed but penetrable opening through the hood and into the medicine in vial 30.
FIG. 2 is a front view of the pharmaceutical vial 30 of FIG. 1 with read seal over-cap in place but unsealed. The capping process entails placing the cap 10 and hood 20 onto the vial 30 as shown. Once fully installed, the aluminum hood 20 is crimped around the neck of the vial 30 to provide a fluid-tight seal.
FIG. 3 is a front view of the pharmaceutical vial 30 of FIGS. 1-2 with read seal over-cap in place and sealed by crimping of the aluminum hood 20.
It would be greatly advantageous to adapt the screw-cap collet chuck design as shown and described in the above-described U.S. patent application Ser. No. 09/222,475 entitled "QUICK-CHANGE COLLET CHUCK", filed Dec. 29, 1998, for use as a collet crimping head to allow crimping of hoods of over caps around the necks of containers such as vials in order to provide a fluid-tight seal.